The endosperm starch of cereal seeds is usually constituted of amylose that is a straight-chain molecule and amylopectin that is a molecule with a large number of branches. If starch is constituted almost exclusively of amylopectin, the starch exhibits the characteristics of glutinous properties such as initiation of gelatinization at a lower temperatures than usual starch, and difficult hardening of starch even after cooling, etc. Therefore, glutinous starch having such characteristics is utilized in a wide variety of applications in the field of food industry.
Conventionally, glutinous corn starch has been exclusively utilized as glutinous starch, but the lack of viscosity stability due to the weakness of starch granule structure constitutes a disadvantage for some applications, so viscosity stability should be imparted artificially by chemical treatment such as cross-linkage using phosphates.
However, processed starch on which viscosity stability has been conferred by chemical treatment is costly and thus priced high, and further such processed starch is against consumers' preference to natural products in the field of food.